Link between anxiety / depression, eating disorders and obesity

Source : Nutriactis/Rouen-Normandie hospital

According to the World Health Organization (WHO), the number of cases of obesity has almost tripled since 1975. As a result, in 2016 and worldwide, nearly 40% of adults were overweight (BMI ≥ 25 kg/m2), with almost 15% obese (BMI ≥ 30 kg/m2).
The increase in the prevalence of obesity worldwide may be partly associated with an increase in the prevalence of anxiety and depressive disorders. In fact, a recent study showed that obese/overweight people and people with EDs were more anxious than those of normal weight were. Around 50% of patients suffering from an EDs also suffer from anxiety or depression.

Anxiety can lead to an increase in emotional eating, which, in the long term, can lead to changes in eating behavior that can lead to the onset of an EDs (see Food fact sheet). As in patients suffering from EDs, deregulation of the gut-brain axis has been observed in anxiety and depression.
In fact, these pathologies can lead to dysbiosis of the intestinal microbiota, frequently observed in patients suffering from EDs or obesity. For example, a lower abundance of Bifid bacterium in patients with high anxiety scores. Similarly, this low abundance was observed in obese patients compared to healthy volunteers.
This dysbiosis of the intestinal microbiota could be at the root of processes such as inflammation, increased intestinal permeability or hormonal disruption, all of which favor changes in eating behavior and the onset of obesity or EDs. Stressful situations could also encourage the consumption of energy-dense foods, and hence the onset of EDs or obesity.

BMI: Body Mass Index, calculated by the following formula: weight (Kg) / height² (m)
Bifid bacterium: Bacterial genus present in the digestive tract, involved in the balance of the intestinal microbiota.

Conversely, obesity could also be the cause of intestinal, which can lead to the apparition of anxiety. Indeed, it is important to remind that diets can have an impact on anxiety levels. In fact, a diet rich in fats and/or sugars can influence the onset of anxiety disorders, while a diet enriched with cereals and vegetables is associated with a depression and anxiety scores.
Finally, one study confirmed that improved weight loss and a reduced risk of quitting when a weight-loss intervention program also includes anxiety management.